While many of us are focused on how much sugar is in food, we really should be focused more on Glycemic Index (GI) – especially if we have type 2 diabetes.
The rate at which a food is broken down in your body during digestion is a lot more relevant to your health than whether the food contains sugar or not.
In fact, some foods that contain sugar are digested more slowly than some that don’t contain any sugar at all, and that has flow-on effects to your energy levels, mood, concentration and weight.
That’s where GI or glycemic index comes in to help.
The Glycemic Index (GI) is a measure of how quickly or slowly a carbohydrate food is digested and increases blood glucose levels.
All carbohydrate foods are broken down into sugars, which are then used by your body’s cells for energy. These sugars fuel your muscles during exercise and are the preferred fuel source for your brain, which uses roughly 20 percent of your daily fuel. Fueling your brain well affects how you think and feel.
HIGH VS LOW GI
High GI foods are broken down into sugars very quickly, causing a ‘spike’ in blood glucose levels, usually followed by a ‘crash’ soon after eating. This can contribute to slumps in energy levels, mood, concentration, and cause cravings for sugary foods.
The sudden rise in blood glucose levels puts pressure on your body to produce more insulin, which over time can lead to type 2 diabetes. Glucose spikes can damage arteries and blood vessels, thus increasing your risk of heart disease.
A high GI intake can also increase your risk of fatty liver, certain cancers and if you have type 2 diabetes, negatively affect eye sight.
High-GI foods are also not helpful for weight control. Significant blood glucose level peaks are followed by big drops, which stimulate hunger, often sending you in search of more ‘quick fix’, high-GI foods and generally encouraging you to eat more.
Foods with a GI of 55 or lower are considered low GI.
Low GI foods break down and release their sugars more slowly, providing a more sustained source of energy. They are not only relevant for those with diabetes and watching their weight, but can benefit everybody.
Eating a low GI intake can:
Help control blood sugar and insulin levels
Reduce your risk of cardiovascular disease and type 2 diabetes
Reduce your risk for certain cancers, including endometrial, breast, colon and ovarian cancer
Reduce LDL cholesterol levels
Reduce the risk for hemorrhagic strokes in women
Encourage fat-burning during exercise
Do I need to eat only low-GI foods?
Looking at the GI of a food can help you make healthier food choices, but you will also need to consider:
Being more mindful of your food portion sizes
Some low-GI foods are high in saturated fat (for example. dark chocolate, pizza and potato chips)
Some higher-GI foods contain important nutrients and don’t need to be avoided (such as watermelon and polenta).
The GI of a food can change when you combine it with another food. For example, wholemeal bread can have a medium-high GI, but a smear of peanut butter will lower the overall GI.
HOW DO I KNOW IF IT’S LOW GI?
Below we’ve ranked some common foods by GI. However keep your eyes peeled for the Low GI Certified symbol on product packaging when shopping.
The symbol was created by the GI Foundation, a non-profit organisation supported by The University of Sydney and Diabetes NSW & ACT, to appear on food packaging to make it easy to identify low GI products. It can be found on a wide range of supermarket foods. They have also developed a Low GI Recipe symbol for recipes that are low GI and meet International Dietary Guidelines.
You can view the full range of low GI certified foods and their recipes on their website here.
GI OF COMMON FOODS
Special K 56
All Bran 44
Porridge (rolled oats + milk) 42
Wonder White 80
Country Life gluten-free multi-grain 79
Wholemeal bread 74
Buttercup fruit and spice loaf 54
Burgen Soy Lin 52
Maggie 2-minute noodles 46
Egg fettuccine 40
White spaghetti 38
Wholemeal spaghetti 37
Jasmine white rice 89
Brown rice 68
SunRice Medium Grain Brown Rice (microwaved), 59
Basmati rice 58
Long grain white rice 50
The GI of a food is definitely worth considering – but there’s no need to avoid nutrient-dense foods with a high GI. Nor is it a good idea to eat as much of a food as you like, just because it has a low GI rating – particularly if you are watching your weight, or if you’re concerned about your blood glucose or insulin levels.
Overall, low-GI foods should be used to supplement other healthy eating guidelines, including eating plenty of fruit, vegetables, wholegrain breads and cereals, and to limit foods high in saturated fats and added sugar.
If you want to know more about the benefits of a low GI-dietary intake, the GI Foundation website is a great resource. It also offers helpful information about managing diabetes and blood glucose levels, and provides low GI recipes and a meal plan to get you started. Visit www.gisymbol.com